Its about revenge for a killing, by way of a pedophilic porn mafia.
The scene is set against a bucolic backdrop of post industrial decline and massive economic distress, especially hard hit areas like 'up north', where the story is set, Gateshead, Newcastle to be precise. The culture difference between down south and up north, was to my memory, quite a thing. Loyalties define and strengthen as you climb the latitudes. That is intertwined in the story through the leash Carter is on.
There's a subtlety here that I feel may be lost on audiences that arent intimately familiar with the regions idiosyncrasies. These are represented in glimpses and furtive glances, beautiful storytelling and documentary all in one.
The film is masterful work, well beyond the linear thinking tough guy's charms and low body movement knock downs of his foes.